Type wheel detent means on calculating machines



Dec. 27, 1949 BQYDEN 2,4923% TYPE WHEEL DETENT MEANS 0N CALCULATING MACHINES 4 Sheets-Sheet 1 Original Filed March 13, 1945 IN VEN TOR. 4 05527 Z. 50 mm R. E. BOYDEN Dec. 27, 1949 TYPE WHEEL DETENT MEANS ON CALCULATING MACHINES Original Filed March 13, 1945 4 Sheets-Sheet 2 INVENTOR.

Past-PT f. BOYDEN Dec. 27, 1949 BQYDEN 2,492,263

TYPE WHEEL DETENT MEANS ON CALCULATING MACHINES Original Filed March 13, 1945 4 Sheets-Sheet 3 INVEN TOR. Pam-A T 5. 50mm 4 Sheets-Sheet 4 Foamr L. 50 mm fiMM EIEIE- R. E. BOYDEN TYPE WHEEL DETENT MEANS ON CALCULATING MACHINES I N VEN TOR.

ATTOQNEY FIE E Patented Dec. 27, 1949 UNITED STATES PATENT OFFICE 7 TYPE WHEEL DETENT MEANS ON I CALCULATING MACHINES Robert E. Boyden, Los Angeles, Calif., assignor to Clary Multiplier Corporation,

Los Angeles,

Calif., a corporation of California Original application March 13, 1945, Serial No.

Divided and this application Decembe! 6, 1946, Serial No. 714,587

6 Claims. (Cl. 101-94) 1 This invention relates to calculating and the like machines and has particular reference to printing mechanisms for use in connection there- Generally, in mechanism of this type, the speed i of the machine must be restricted to a point where the usual yieldable detenting devices may operate safely or the timing of the machine is so arranged that the driven element or the unit is safely arrested by its driver before the demeshing operationis commenced so that the element cannot overthrow or rebound from its yieldable pawl. However, such arrangement of timing generally results in crowding of other phases of the machine cycle with consequent final limiting of the machine speed.

Also, attempts made heretofore to positively detent the driven elements have met with difliculty in view of the bodily movement of such elements into and out of mesh with their drivers.

One object of the present invention to provide a detenting device which positively prevents overthrow or rebound of a driven element such as a printing wheel, regardless of such tendencies when the element is disengaged from its driver.

Another object is to provide a spring urged detenting device of the above type which is nor.- mally suflicient under its spring urge to effect a detenting function which will be positively operated if the spring urge is insufficient. Another object is to provide a detenting device fora geared element, such as a printing wheel, which element is carried to and from meshing engagement with the driving device therefor, such detenting device being eilective to positively prevent overthrow of the geared element and which is renderfed ineffective to perform a detenting function when the geared element is brought into meshing engagement with its driver. Another object is to facilitate removal of a printing unit from a calculating machine.

The manner in which the above and other ob- 2 a jects of the invention are accomplished will be readily understood on reference to the following specification when read in conjunction with the accompanyin drawings, wherein: I

Fig. 1 is a plan view of a machine embodying a preferred torm'of the invention. 1 Fig. 2 is a longitudinalsectional view, with parts broken away, of the machine, illustrating the printing mechanism and themeans for controlling registratlon thereof.

Fig. 3 is a sectional view similar to that of Fig.

2 but illustrating the printing mechanism in aphase partially through its operation. Fig. 4 is a side view illustrating the controlshaft operatin means.

Fig. 5 is an enlarged front view of of the printer control mechanism and is taken substa tially along the line 5-! of Fig. 2. Fig. 6 is a sectional plan view of the condens ing arrangement for transmitting a drive from the drive racks to the printer mechanism and is taken along the line 6-8 of Fig. 2. The present invention is disclosed in connection with a motor operated, key controlled addin machine of the type disclosed and claimed ,in the copending application of Robert E. Boyden,

Serial No. 582,553, died March 13, 1945, and entitled "Calculating machine. The present application is a division of said copending. applica- I tion and reference is hereby made thereto for an understanding of details of the machine not'sp cifically disclosed herein. However,. it is to be understood that at least certain phases of the invention may be applicable-to other types of mechanisms and other types of machines.

Referring in general ,toFig. 1, an amount to be added or subtracted is entered in the machine by'depressing appropriate amount keys 9. In

order to add this amount into an accumulator,

one or the other of two add bars ill and H is dean amount stored in the accumulator, a minus I bar I3 is depressed.

If it is desired to print an amount setup on the keys 9, but not to add the same in the accumulator, a "non-add bar it is depressed. If it is desired to add the same amount in thesecumulator two or more times, a repeat bar i5 is depressed and held down until the requisite number of additions are made by the machine.

If a. wrong amount is set up on the keys 9, the

. 3' rection" bar I6 which releases the keyboard without starting the motor.

If it is desired to obtain a total of a value registered on the accumulator, a "total" bar I1 is depressed. In the event it is desired to obtain a sub-total, a sub-total bar I8 is depressed.

The control mechanism rendered effective by depression of the various aforementioned control bars, as well as the operating mechanism of the machine, is omitted in this application for the sake of brevity and clarity, since it is not deemed necessary for an understanding of the invention. However, it should be noted that the operating mechanism includes a cyclic shaft I' (Figs. 2- and 4) which, upon a momentary depression of any of the control bars III, II, I3, I4, I5, I1 or I8 is given a single complete rotation to effect a cycle of operation of the machine.

The keyboard comprises a series of rows of amount keys 9, the key stems 29 of which are slidable in aligned slots formed in a top plate 21 and a'key frame 2|. The keys in each bank are yieldably pressed upward by a tension spring 32 extending the length of the keyboard and suitably'attached at opposite ends to the plate 21. Upon depression of a key, the adjacent portions of the spring are stretched to yieldably urge the keyv toward its raised position.

Means are provided for locking depressed keys in their lowered positions and for releasing any such depressed keys. Each key stem has a cam (not shown) formed thereon which, when the key is depressed, rocks a locking ball 38 pivoted at opposite ends thereof to the front and rear side walls of the frame 2| by trunnion bearings 39 and 40. At the end of its stroke, the cam' lobe passes below the bail, enabling the latter to retract partially under the action of a spring (not shown) to a position where it latches the key depressed.

A zero stop 42 is attached to each locking ball 30 and, when no key in any one order is depressed, the bail 38 of that order will be spring held in an extreme inwardly rocked position in which the zero stop lies directly in front of one of a series of shoulders 19 formed on an associated drive rack I9, thereby preventing any substantial forward movement of the rack during subsequent phases of a machine operation. However, when any amount key in that order is depressed and latched down, the locking bail will be held outward'sumciently to maintain the associated zero stop out of the path of the aligned rack while the key stem of the depressed key will be positioned in front of one of the series of shoulders 19 on the aligned rack IS. The shoulders are so spaced that the rack will subsequently be allowed to move forward a number of increments equal to the value of the depressed key before being arrested thereby.

Referring to Fig. 2, each of the drive racks I9 is provided with elongated slots 80 and I30 fitted over shafts II and Ill, respectively, forming supporting and guiding means for the racks.

Each of the slots I30 terminates in opposed lateral depressions 14 at its closed end. Each of these depressions is normally engaged by a roller 15 carried by a drive element I6 which is rockably fitted within a groove in the shaft 10. The adjacent drive elements 16 associated with any one rack I9 are spring urged in opposite directions about shaft 10 by a tension spring 11 connected between the tails of the two elements, thus forming a yieldable connection between the shaft and the respective drive rack I8.

During a cycle of operation of the machine the shaft III is moved forwardly along slots I3 formed in machine frames (one of which is shown at 24) and in so doing, the various drive elements I6 carry therewith the racks I9 until they are stopped by the key stems of any depressed keys, or a stationary 9 stop bar 420 in the event a 9" amount key is depressed. In case no key in any one order is depressed, the drive elements IS in that order will be ineffective to drive the associated rack. At such time the rollers 15 will ride out of the depressions 14 against the action of spring I1, thus breaking the connection between the shaft and the racks.

A pair of opposed rack gear sections 83 and 84 are disposed on opposite sides of an associated accumulator gear or element and thus serve to selectively rotate the gear in either of opposite directions, depending upon the vertical setting of a shaft 86 supporting the latter gears.

In order to accurately locate each drive rack I9 in any of its incremental positions, a locking bail 88 is provided, being pivoted on trunnion bearings "I and movable into any of a series of notches 81 which are spaced apart distances equal to the diiferent increments of movement of the rack. The ball is normally in locking engagement with the rack but is moved outward from engagement therewith during the forward and return travel of the rack.

Printer The printer comprises a series of numeral printing dials or elements I35 equal in number to the number of drive racks I9. Each numeral dial has thereon a series of type characters ranging progressively in value from 0 to 9, and these dials are so connected to the associated racks that each will print a digit corresponding to the value of the amount key depressed in the associated key bank or to the numerical position to which the rack is moved in its forward stroke.

Each printer dial I35 is rotatably mounted on a separate arm or carrier I36 which is loosely keyed on a printer control shaft I31 and spring urged clockwise by a tension sprin I38 extending between the arm and a suitable portion of the machine frame. Each dial I35 has integrally secured thereto a gear I39 permanently meshed with a gear I40 also rotatably mounted on the associated arm I36. When an arm I38 is held in its normal position illustrated in Fig. 2 by the shaft I31, the gear I40 is meshed with an aligned one of a series of large idler gears I4I rotatably mounted. on a cross shaft I42. The latter idlers are continuously entrained with respective ones of the drive racks I9 through a series of pinion assemblies to be described presently.

At approximately the mid-point in a machine cycle, and after the racks have digitized the accumulator and printer, the printer control shaft I3! is rocked clockwise permitting the springs I" to rock those printer arms I38 which are otherwise allowed to do so, and thus carry the printing dials I35 forward into contact with a printing ribbon I44 and the paper strip 8 carried around the periphery of the platen I2, whereby the value registered on the dials will be printed onto the paper at the-printing point.

Referring to Fig. 4, the shaft I31 is securely fastened to a lever I45 urged clockwise by a strong tension spring I46 and provided with a roller I 41 held against a camming lever assembly I48 pivoted on a shaft 8|. A roller I50 on the lower end of the lever assembly rides on the periphery of a cam III keyed to the aforementioned cyclic shaft 6|. Thus. as the shaft 5| rotates through approximately 180 degrees of its 'cycle, the spring I46 becomes effective to rock zeros to the left of the highest significant digit being printed while enabling all zeros to th right thereof to be printed. For this purpose, a latch I52 (Figs. 2, 3 and 5) is provided adjacent each arm I36 and is journalled on a stationary cross I53 extending through 'cam slots I54 in the various idler gears Ill. The levers I52 are urged clockwise by tension springs I55 extending between the levers and a cross rod I56, and are provided with ears I51 adapted to normally overlie a foot I58 extending forwardly from an aligned arm I36 when the associated drive rack I9 is located in a zero or home position.

A roller I59 rides in the cam slots I54 and,

when the associated mm m and the printing dial I35 are retained atlzero position, the contour.

of the cam slot enables the spring I55 to maintain the lever I52 in its full clockwise rocked posi-- tion, as illustrated in Fig. 2, wherein it overlies the foot I56 and thus prevents the latter from being rocked clockwise during the printing operation, However, when any idler gear MI is rotated to its "one or any other position, its cam slot I54 will rock the associated lever I52 outward to the position illustrated in Fig. 3, thereby enabling the associated arm I36 to be subsequently rocked by its spring I36.

As will be noted in Fig. 5, each of the latch levers I52 is provided with an ear I66 overlying the corresponding car on the similar lever located to the left in thenext denominationally higher order. Therefore, when any latch lever I52 is rocked outwardly by its idler I4I, all of the levers I52 to the right thereof will likewise be rocked outwardly by virtue of the overlapping ears I66. a

In order to hold the various idler gears MI in registered positions-after being angularly adjusted thereto by the drive racks I9, a locking bail 436 is provided which normally engages between two of the teeth of each of the idlers I4I. During a digitizing operation of the racks.'however, and also during return'of the racks to their home positions, the ball is disengaged from the idlers.

According to the present invention, means are provided for retaining each printing dial I35 in its angularly adjusted or registered position after the associated gear I46 entrained therewith is demeshed from its idler I4I upon clockwise rocking movement of the associated arm I36.

I For th s purpose a detenting or centralizer pawl I6I is pivoted at I62 on the associated arm,

I36 and has a tooth' I63 adapted to engage between two adjacent teeth of the dial gear I39. A tension spring I64 extending between the pawl and the lever continuously urges the pawl toward engagement with the gear. However, when the printing arms are rocked into their normal positions illustrated in Fig. 2, a tail I6Ia on each of the pawls engages a stationary crossbar I65, thus holding the pawls out of engagement with the gears I39 so as to reduce any drag on the entrained gearing and the drive racks during their forward digitizing movement.

It should be noted that the arrangement of the stationary rod I65 is such that the pawls I6I are not disengaged from the dial gears I39 until the gears I46 move at least partially into mesh with their respective idlers I4I.

During the printing operation, and when the arms I36 are rocked clockwise by their springs, the pawls I6I recede from the rods I65, enabling the springs I64 to rock the latter into engagement with their respective dial gears I39. This engagement of the pawls is intended to become effective before the gears I46 become demeshed from the idlers I so as to prevent any rotation of the dial gears after the arms I36 rock toward the platen. At speeds up to a certain amount,

the springs I64 are normally effective in themselves to move the pawls into detenting position and thus prevent any overthrow or rebound of the dialsbeyond their registered positions. However, at higher speeds, and, particularly, where the timing is so close that the idlers I4I come to rest just as the arms I36 move toward the platen the momentum of the dials might be sufficient to normally force the pawls I6I against the action of their springs and out of engagement with the gears I39 or the dials may be able to rotate because of their momentum after the gears I46 leave mesh with the idlers HI and before the spring I64 is eifective to force the pawl I6I into detenting position. In order to prevent this possibility and to render the pawls I6I absolutely positive in operation, a second stationary rod I66 is located above the tail I6 Ia of the pawls so that as the arms I36 carry the' latter upwardly and rearwardly during the printing operation, the tails are adapted to strike the rod I66 in the event that they are not moved sooner by their springs I64 and may thus be positively forced in a counterclockwise direction relative to the arms I36 and into engagement between adjacent teeth of the gear I39. It will be noted that this positive detenting movement of the pawls I6I will become efiective before the gears I46 are completely demeshed from idler gears I4I.

Describing now the means for connecting the various idler gears I4I with their associated drive racks I9 in order to register the printing dials in accordance with the numerical positions to which their associated drive racks I9 are moved, a series of shafts I61 to I16, inclusive (Figs. 2, 3 and 6), are journalled on stationary frame plates I12, I13, etc., and carry various pinion assemblies which are arranged to entrain the idlers I with their respective racks I9. For

example, a. rack gear section 82 (Fig. 2) of the rack in the #1 or right hand order of the machine is meshed with a pinion I14 fixed on the shaft I16 to which is also fixed a pinion I15 meshing with the #1 idler I 4I and entrained with the cents column numeral printing dial I35 -(Figs. 2 and 3). In Figs. 6, this idler is located next to the right hand idler I, the latter being reserved to print a symbol character in amanner not shown. Similarly, the rack in the second order from the right is connected by a pinion I16, shaft I69 and pinion I11 to the #2 idler. The rack in the third order is connected by pinion I16, sleeve I19 (rotatably mounted on shaft I61) and pinion I66 to the #3 idler. The rack in the fourth order is connected by a pinion I8l sleeve 182 (rotatably mounted on shaft I68) and idler order is connected by a pinion I81, shaft- I88 rack in the eighth order is connected by pinion' I93, shaft I61 and pinion I94 to'the #8 idler; The rack in the ninth order is connected'by pinion I95, shaft I58 and pinion I96 to the #9 idler.

The various supporting plates I12 and I13 support the various elements of the printer, includ- The rack in the seventh orders coning the shafts I42 and I61 to I10, inclusive, independently of the supports for the racks I9 so that the printer may be readily removed as a unit from the machine, the various pinions demeshing from the racks.

The machine is encased in a cover 3Iil of plastic or similar material and in order to obtain maximum visibility of values recorded on the paper strip 8 (Figs. 2 and 3) and also to effectively cover the printing mechanism, a movable cover section a 455 is mounted in an opening formed in the cover section adjacent the platen I2. The cover section is pivoted on trunnion bearings 458 adiacent the forward end thereof to the casing I and extends over the printer mechanism to a point adjacent the platen I2. The .sectlon 455 is urged downwardly into its normal position shown in Fig. 2 partly by its own weight and partly by a spring 451 extending between projections on the section and on the casing 35L An arm 458 attached to the section 455 extends downward and has a cam surface on the lower edge thereof which overlies aroller 459 carried by an arm 460 which is securely keyed to the aforementioned printer control shaft I31.

Normally, except during a printing operation, the section 455 lies in the position illustrated in Fig. 2 the rearmost edge of the latter being positioned directly below the location of the last printed value appearing on the paper tape 8 i the tape having been advanced an increment by means not shown as an incident to printing of said last value).

During a printing operation, the shaft I31, when rocked to allow the printer arms I 35 to rock clockwise will cause arm 450 to cam the arm 455 and cover section 455 upward sumciently to allow the printing dials I35 and pawls I II to pass thereunder into the position illustrated in Fig. 3.

Certain of the subject matter disclosed but not claimed herein is disclosed and claimed in my copending applications, Serial No. 718,706, flied on December 27. 1946, and Serial No. 116,253, filed on September 17, 1949.

Although I have described a preferred embodiment of my invention in detail and have therefore used certain specific terms and languages herein. it is to be understood that the present disclosure is illustrative rather than restrictive, and changes and modifications may be made without departing from the spirit or scope of the invention as set forth in the claims appended hereto.

Having thus described the invention, what I desire to secure by United States Letters Patent is:

1. In a calculating machine. printin mec anism comprising the combination of a platen, a nivotal tyne element having type characters on the periphery thereof, a first gear attached to said element, a second gear meshing with said first gear. means including a drive gear adapted to mesh with said se ond gear for advancing said type element to position selected type characters in printing relation to said platen; a rockable arm supporting said first and second gears and said platen, a detenting device carried by said am and engageable with said first gear, camming means engageable by said detenting device upon movement of said arm from said normal position and before the teeth of said second gear are demeshed from the teeth of said drive gear for moving said detenting device into detenting engagement with said first gear. and camming means engageable by said detenting device upon movement of said arm toward said normal position and after the teeth of said second gear are meshed with the teeth of said drive gear for releasing said detenting device from detenting engagement with said first gear.

2. In a calculating machine, printing mechanism comprising the combination of a platen, a pivotal type element having type characters on the periphery thereof, av gear device operatively connected to said type element, means including a drive gear adapted to mesh with said gear device for advancing said type element to position selected type characters in printing relation to said platen; a rockable arm supporting said gear device and said type element, means for rocking said arm between a normal position wherein said drive gear meshes with said gear device and a printing position wherein said gear deviceis out of mesh with said drive gear and wherein said type element contacts said platen, a detenting device carried by said arm and engageable with said gear device, means engageable by said detenting d8? vice upon movementof said arm from said normal position and before the teeth of said gear device are demeshed from the teeth of said drive gear for positively moving said detenting device into detenting engagement with said gear devire. and means engageable by said detenting device upon movement of said arm toward said normal position and after the teeth of said gear device are meshed with the teeth of said drive gear for positively releasing said detenting device from detenting engagement with said gear device.

3. In a calculating machine, printing mechanism comprising the combination of a platen, a pivotal type element having type characters on the periphery thereof, a gear device operatively connected to said type element, means including a drive gear adapted to mesh with said gear device for advancing said type element to position selected type characters in printing relation to said platen: a rockable arm supporting said gear device and said type element, means for rocking said arm between a normal position wherein said drive gear meshes with said gear device and a printing position wherein said gear device is out of mesh with said drive gear and wherein said type element contacts said platen, a detenting device carried by said arm and engageable with .said gear device, spring means for normally urging said detenting device into detenting engagement with said gear device, means engageable by said detenting device .upon movement of said arm from said normal position and before the teeth of said gear device aredemeshed from the teeth of said drive gear for positively moving said detenting device into detenting engagement with said gear device against the action of said spring means, and means engageable by said detenting amazes device upon movement of said arm toward said normal position and after the teeth of said gear device are meshed with the teeth of said drive gear for positively releasing said detenting device from detenting engagement with said gear device.

4. In a calculating machine, printing mechanism comprising the combination of a platen, a pivotal type element having type characters on the periphery thereof, a gear device operatively connected to said type element, means including a drive gear adapted to, mesh with said gear device for advancing said type element to position selected type characters in printing relation to said platen; a support for said gear device and said type element, means for moving said support between a normal position wherein said drive gear meshes with said gear device and a printing position wherein said gear device is out of mesh with said drive gear and wherein said type element contacts said platen, a detenting device carried by said support and engageable with said gear device, means engageable by said detenting device upon movement of said support from said normal position and before the teeth of said gear device are demeshed from the teeth of said drive gear for positively moving said detenting device into detenting engagement with said gear device, and means engageable by said detenting device upon movement of said support toward said normal position and after the teeth of said gear device are meshed with the teeth of said drive gear for releasing said detenting device from detenting engagement with said gear device.

5. In a calculating machine, printin mechanism comprising the combination of a platen, a pivotal type element having type characters on the peripher thereof, a gear device operatively connected to said type element, means including a drive gear adapted to mesh with said gear device for advancing said type element to position selected type characters in printing relation to said platen; a support for said gear device and said type element, means for moving said support between a normal position wherein said drive gear meshes with said gear device and a printing position wherein said gear device is out of mesh with said drive gear and wherein said type element contacts said platen, a detenting device carried by said support and engageable with said gear device, camming means stationary with respect to said support and engageable by said detenting device upon movement of said support from said norma1 position and before the teeth of said gear device are demeshed from the teeth of said drive gear for positively moving said detenting device into detenting engagement with said gear device, and second camming means stationary with respect to said support and engageable by said detenting device upon movement of said support toward said normal positionand after the teeth of said gear device are meshed with the teeth of said drive gear for releasing said detenting device from detenting engagement with said gear device.

6. In a calculating machine, printing mechanism comprising the combination of a platen, a pivotal type element having type characters on the periphery thereof, a gear device operatively connected to said type element, means including a drive gear adapted to mesh with said gear device for advancing said type element to position selected type characters in printing relation to said platen; a support for said gear device and said type element, means for moving said support between a normal position wherein said drive gear meshes with said gear device and a printing position wherein said gear device is out of mesh with said drive gear and wherein said type element contacts said platen, a detenting device carried by said support and engageable with said gear device, a spring for normally urging said detenting device into detenting engagement with said gear device, camming means stationary with respect to said support and engageable by said detenting device upon movement of said support from said normal position and before the teeth of said gear device are demeshed from the teeth of said drive gear for positively moving said detenting device into detenting engagement with said gear device against the action of said spring means,'and second camming means stationary with respect to said support and engageable by said detenting device upon movement of said support toward said normal position and after the teeth of said gear device are meshed with the teeth of said drive gear for releasing said detenting device from detenting engagement with said gear device.

ROBERT E. BOYDEN.

REFERENCES CITED The following references are of record in the file of this patent:

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